Contact-protecting means for vacuum tubes



Sept. 18, 1928.

. s. G. SEARS CONTACT PROTECTING MEANS FOR VACUUM TUBES Filed Sept. 12, 1925 ,INVENTOR flzzwz/wa 61/535606 j AT ORNEY Patented Sept. 18, 1928.

UNITED STATES PATENT OFFICE.

STERLING G. BEARS, OF BROOKLYN, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO NAYLOR RADIO CORPORATION, OF NEW YORK, N. Y.

QI'ON'JPAC'ZI.4913.0TECTING- MEANS FOR VACUUM TUBES.

Application fled September 12, 1925. Serial No. 55,989.

contactprotecting means for vacuum tubes.

The contact pins of vacuum tubes of all kinds frequently, during use, become coated 5 withthe oxides of the metals of which the pins are made, thus creatm high resistance and reventing pins from e ciently performing t eir contacting function, and it is one of the objects of this invention to protect such contact pins of vacuum tubes from such oxides and also to protect the same from grease and dirt which collects on the rough surfaces of such metal ins.

Another 0 ject of this invention is to produce a protective cap for such contact pins having its contact surfaces coated with a precious or non-oxidizing metal'and preferably to provide a cap whlch 1s adapted to fit snugly over such pins and to have a frictional engagement therewith.

Another object of this invention is to produce a metal cap in which the s rin for retaining it in place on the in wi 1 be inherent in the material of which t e cap is made, and 25, will preferabl be provided by forming slits or splitting t e cap vertically mto resil ent sections or prongs which willenable a slight ex ansion of the cap during attachment-but wi enable a ver snug frictional enga ement with the pins to be procured an a clipping in place of the same without mum to the bulb. v

Another object of this invention is to provide means for len hening the contact members slightly and t us causing a greater depression of the contact springs dunng nsertion of a bulb in its socket and producing a more effective contact with the socket springs. With these and other objects view, the invention comprises the combination of members and arran ement' of parts so combined as to co-act an% cooperate w1th each other in the erformance of the functions and the accomp 'shment of the results herem contemplated, and comprises in one of lts adaptations the species or preferred form illustrated in the accompanymg drawings, m which:-

Fig. 1 is a section through a vacuum tube socket showing an elevation of a vacuum tube mounted in said socket and showing my improved contact cap applied to the contact pins of the tube g Fig. 2 is a plan view of the bottom of a vacuum tube showing contact caps in place upon the pins;

Fig. 3 is a vertical section through one of the1 contact caps mounted on a contact pin; an

Flg. 4 1s a perspective view of a contact cap embodying my invention dismounted from the pin.

Referring now to these drawings which Illustrate a preferred embodiment of m invention 1 indicates a contact cap whic as illustrated, is preferably stamped up into cup shape so as to provide a body portion 2 having its interior surface 3 conformin with the shape of the pins 4 which are usuafiy cyhndrical and as shown, my improved cap is composed of a cylindrical body portion 2 and a mouth or entrance opening portion 5 flared upwardly from such body portion to permit ready connection with the pin to which it is adapted to be attached. The inner surface of the body portion is preferably adapted to bee snu fit overthe end and shank of the pm 4 arm the mouth is adapted to engage the ase portion 4 of the pin so as to snugly clip over the in and to maintain a firm and close connectlon therewith. My improved contact caps are preferably formed of thin sheet metal and the inner and outer surfaces thereof are preferably plated with gold or other non-oxidizing metal so as to prevent the formation of oxide at the connection between such pins and the caps and between such caps and the contact plates or springs with which they are maintained in contact. Obv ously, when the caps of my invention are sllpped over contact pins of a tube, the formatlon of oxldes will, because of the plating of thecontact caps, be entirely prevented and the resistance due to the formation of such oxides between the contacts will be avoided. The pins will thus be enabled to erform their functions more efficiently and t e tubes will likewise operate with greater efliciency on account of t e better connection and the avoidance of resistance at such, connection. Furthermore, it will be seen thatthe'attachment of m caps to contact pins of a bulb lengthens t e bulb contact members slightly.

thus causing a greater depression of the contact springs 6 in the socket 7 and producing a more effective contact with such socket 5 springs.

Hav ng described my invention, I claim 1. In a contact protecting means for vacuum tubes having pins of oxidizingmetal, contact caps formed of spring metal and having contact surfaces coated witha non-oxi- 3. In a contact protecting means for vacdizing metal. uum tubes having contact ins of oxidizing 2. In a contact protecting means for vacmetal, an outer shell form of non-oxidizing uum tubes having pins of oxidizing metal, metal fastened'to said in.

5 contact caps composed of sprin metal hav- In witness whereof, have signed my name a ing cylindrical body portions an flared open to the foregoing specification.

' ends and provided with contact surfaces Y plated with a non-oxidizmg metal. 7 STERLING G. SEARS. 

